Images slow to appear in Photoshop Main Window

After I have uploaded an image in to Photoshop CC it fails to appear immediately, sometimes taking a full minute to appear. Even though the image appears in the 'Layers' column [See attached image]. I move around the screen in the hope of sparking it in to action but nothing.

Images slow to appear in Photoshop Main Window

After I have uploaded an image in to Photoshop CC it fails to appear immediately, sometimes taking a full minute to appear. Even though the image appears in the 'Layers' column [See attached image]. I move around the screen in the hope of sparking it in to action but nothing.